Magnetically operated switches



April 19, 1966 R. H. VAN WAGENER E MAGNETICALLY OPERATED SWITCHES 2 Sheets-Sheet 1 Filed Oct. 22, 1963 m I 8 0 Fkm 1 4 2 H I m. M J M 1 \1 a w n 2 f 9 B I v L FIG.|. FIG.2. FIG.3. FIG.4.

FIG .7.

INVENTORS Raymond H. Van wagenera FIG.6.

FIG.5.

Humfrey N. Udall ATTORNEYS April 1966 R. H. VAN WAGENER ET AL 3,247,343

MAGNETICALLY OPERATED SWITCHES Filed Oct. 22, 1963 2 Sheets-Sheet 2 R d H v vIJNVENTORg oymon an ugener H G Humfrey N. Udall M4 @AMMM ATTORNEYS United States Patent 0 3,247,343 MAGNETICALLY OPERATED SWITCHES Raymond H. Van Wageuer, loroton, and Humirey N. Udall, Darien, C0nn., assignors to American Machine & Foundry Company, a corporation of New Jersey Filed Oct. 22, 1963, Ser. No. 318,019 10 Claims. (Cl. 200-87) This invention relates to magnetically operated switches, and more particularly to sealed switches that are operated by induced magnetism from permanent magnet or electromagnetic operators.

In known forms of magnetically operated switches, the magnetic operator is effective to induce a magnetic field that causes the switch contacts, or magnetic material associated with the contacts, to have a mutual attraction to operate the contacts. The most common of such switches is the reed switch which usually comprises a pair of elongated and overlapping resilient reeds of nonretentive magnetic material sealed in a nonmagnetic, nonconducting enclosure.

In the usual arrangement of such reed switches, the magnetic actuator is a coil that encircles the nonconducting enclosure to induce an axially directed magnetic field which magnetizes the resilient reeds to opposite polarity so that contacts on the reeds operate by mutual attraction of the reeds. In another arrangement, a magnet disposed perpendicular to the axis of the nonconducting enclosure is effective to magnetize the resilient reeds to opposite polarity so they attract each other to operate the contacts carried by the reeds. A serious disadvantage of such arrangements is the relatively large amount of space required when large numbers of reed switches are used. Where the operating coil encircles the reed switch, the total diameter of a single switch unit is that of the outside diameter of the operating coil. Where the mag' net that operates the switch is perpendicular to the axis of the enclosure and adjacent a side wall thereof, it is necessary that at least a portion of the side of each switch enclosure be exposed to operate the switch.

In another known form of reed switch, the reeds each project through the same end of the enclosure to provide leads for attaching the switch to suitable circuitry. In

that construction, the switch contacts are operated by:

magnetizing the leads to opposite polarity so that the contacts close by mutual attraction. Although it is possible to arrange such reed switches in close side-by-side multi-layer relation, numerous additional problems arise when it is desired to operate the switches in sequence. Such problems include proper insulating of the leads aswell as special magnetic material supports for the switches.

In this invention, the problems previously encountered are overcome. The switch of this invention includes a pair of opposed magnetic members that are movable to.

open and close an associated set of contacts. The contacts are operated by a magnetic operator disposed adjacent an end of the switch envelope, the magnetic opera-- tor being effective to create a magnetic field which induces like poles in each of the magnetic members while simul-- taneously attracting the magnetic members toward the positioning the magnetic operator one or the other of The effect.

the forces is made predominate so that a normally open switch closes, or a normally closed switch opens.

When the magnetic operators are disposed beyond the ends of the enclosures or enevelopes of the switches, the switches themselves may be grouped very closely with their envelopes in contacting relation if desired. Since the sides of the enclosures need not be exposed, it is apparent that the switch units can be positoned very close to each other and, if desired, in several adjacent layers with several switches in each layer. It is to be further appreciated that the switches can be arranged in almost any array with corresponding space saving and that normally open and normally closed switches can be used in side-by-side relation for actuation by the same magnetic operator.

In view of the foregoing, an object of the present invention is to provide an improved magnetically operated switch that can be reliably operated by a magnetic operator adjacent one end of the switch.

Another object is to provide a magnetically operated switch in which magnetic members associated with the contacts are simultaneously magnetized to like polarity and attracted toward a magnetic operator to operate the contacts. 7

Another object is to provide a nonrnally open reed switch that is operated by a magnetic operator adjacent an end of the switch and a normally closed reed switch that is operated by the same magnetic operator.

A further object of the present invention is to provide a reed switch in which the resilient contact members extend through and are supported by one end of a dielectric envelope and the contacts are disposed adjacent the other end of the envelope for operation by a magnetic operator outside the envelope which is axially aligned with the envelope and adjacent the end thereof.

-A further object is to provide a reed switch which is especially adapted to be arranged with a plurality of like switches for operation insequence by a magnetic operator.

A still further object is to provide a reed switch of such construction that a plurality of switches are readily disposed in close contacting, multi-layer, side-by-side rela-- tion for operation by a magnetic operator or operators at an end of the switches.

Numerous other objects and advantages of the present invention will become apparent from consideration of the following detailed description in conjunction with the drawings which form a part of this specification and in which:

FIG. 1 is a front elevational view in section of a normally open switch forming a first embodiment of the invention;

FIG. 2 is a side elevational view in partial section looking along line 22 of FIG. 1;

FIG. 3 is a front elevational view in section of a normally closed switch which forms a second embodiment of this invention;

FIG. 4 is a side elevational view in partial section looking along lines 4-4 of FIG. 3;

FIG. 5 is .a line drawing illustrating the principle of operation of the switches of this invention;

FIG. 6 is an enlarged partial view of the switch of I FIG. 1 showing the operation of the switch by a magnetic operator;

FIG. 7 is an enlarged partial view of the switch of FIG. 3 showing the operation of the switch by a magnetic operation;

- FIG. 8 is a perspective view of one preferred assembly arrangement of a plurality of switches and magnetic operators of the present invention;

FIG. 9 is an end view of another preferred assembly arrangement of the switches; and

FIG.-10 is aview in exploded perspective of an assentbly arrangement for sequential operation ofthe switches.

Referring now to the drawings in detail and particularly to FIGS. 1 and 2, there is shown a reed switch 1, having a sealed, elongated,.tubular envelope 2of-dielectric material, and apair of reeds'l'vrand l:

Reeds 3 and '4 pass through andv are sealed tosan end 5 of envelope 2, to forma pair oflextemai electrical' terminals 6. Reeds 3. and 4-are= formedl from flexible, nonretentive, magnetic materialLhaving good electrically conducting properties: The-.reeds are elongated and extend axially inside envelo'pea2 to'termin'ateadjacent. the.- inside of a generally sphericalfend- 7 of the envelope;

Reeds 3' and4 includezelongated, .spacediapart, contact.

arms Sand 9,1conveniently showniinr parallel relation '6 and 12, may be suitably formed to be connected to a circuit in other known ways. The only significant difference between these switches resides in the configuration of the end members and the direction in which the end members of the respective switches are elongated.

A distinct advantage of the switches of FIGS. 1 and 3 is that both switches can be'operated by the same elec :tromagnetic or permanent actuator by disposing the actuzator in proximity of the end of. the envelope so that the :magnetic forces of the actuator influence the unsupported magnetic ends of the needs, to. move the contacts ship, the unsupported ends: ofwhich: are deformed to.

provide inwardly projecting;transversely: aligned contactss lfland "11, and' aligned: elongated: magnetic end? meme bers 12 and 13 that project in opposite directions fronn the extreme. ends of the-reedalongi the same: axis per pendicular to the axis 'of=envelopei:2.. It-will=-be.apparent-that the reed membersfi and 4need-not be parallel" but may converge or divergeg 'be concave or convex andi the like. The reed shown is 1 circular in cross-section,

although the cross-section may berrectangular, or have other configurationif desired. Contacts" 10and 11 are: preferably plated with i a suitable: contact material such; as rhodium to prolong the life of the contacts. Inxthe'; embodiment of theswitch -shown iniFIGS: 1 and 2,.

the contact arm's's and 9are sufliciently resilient to maintain contacts 10 anddlfin-spacedapart relation to'pro-- vide a normally open switch.

In the embodiment-of FIGS.'- 3 and. 4; there is shown; a normally'closed reed-switch l li Reed switch 14-=is.

similar to' reed switch 1,-havinga-cylindrical envelope-a;

bers 22 and 23 which project parallel to each other in.

a transverse direction perpendioular to the longitudinal axis of' envelope-151* sifice reed's-lo'and: 17 are; essen- Y tia'lly parallel with"the'lotig itudinal axis of'envel'ope 15,;- the reeds are h shaped w'lien viewedin side: elevation; as shown in FIG. 4. Due to the resiliency of contact.- arms 19 and 20,"en d 'members 22-and 23 are normally biased into engagement'with each other, the engaging-v portions of. end members 22 and? 23 being plated with:

suitable contact material to provide electrical contacts 22, and 23 (FIG. 7) for reed switchr 14..

Thus, it is apparent' that-reed "switch -1, shown. in FIGS; 1 and 2"is substantially identicat'to reed switch 14, shownin FIGS. 3 and 4. Both switches are essena tially of the same length and-diameter, each having an elongated, sealed, dielectric-envelope, with each switch t'orrned of 'the same material. End members 12 and 13 of the reeds 'ofi'switch 1' are spacedxthe same distance from end 70f envelope 2 as end members' 22 and -22: of switch 1 4 arespaced fI'OIIt end 24 of envelope 15., In both switch 1 and switch 14, the contacts are located adjacent the unsupported ends of the reeds. As viewed in front-elevation in FIGS. 1 and 3, switch 1 and switch 14 are each symmetrical relative to the central longitudinal axes of their respective envelopes. Terminals 6' and 18' of the respective'switches have the same cross-sectional configuration and spacing so that either switchcan be plugged into a :mating electrical ocket (not shown); Alternatelythese-terminals,

the reeds ofon the reeds from one position to another, against the bias of the resilient contact armportions of the reeds.

The principle of operation of the switches of FIGS. 1 :and 3 is illustrated in FIG. 5. As shown, members 25. :and 26 are strips of flexible, nonretentive, magnetic ma- Tterial, and magnet 27 (which maybe apermanent mag- .net or energized. electromagnet) is positioned close enough to the ends of the strips to influence these ends :magnetically. Magnet 27 is disposed so that its magnetic axis 28 (i.e., its central axis extending from the :north pole to the south pole of the magnet) is midway between and parallel with the strips. For purposes of -explanation assume the north pole of the magnet to be closest to the ends of the strips sothat the strips arev attracted toward the magnet; It is believed that the efiect of the magnet whenso positioned is to induce poles of different polarity from that of the pole of the magnet closest to the strips, attheend of each oi? the strips. Hence, the magnetism from the magnet iseffective to produce south poles at the end of each of the strips" 25, 26, since the north pole of the magnet is-closest to the strips. By virtue of the attractive forces of the magnet, strips25, 26 are pulled toward the magnet in the direction indicated by the vectors A and, A A repre sentingthe force exerted by the magnet on; strip 25 and A representing the force'exerted. by the magnet on strip 26. Sincestrips25 and 26 are identical and are equally spaced from magnet 27 the. forces represented by vectors A and A are equal. Resolving vectors A and A into their rectangular coordinate components parallel with": and, perpendicular to the magnetic. axis 26'are magnetized to like polarity. Sll'lCCilt'lS well known:

that like magnetic poles repel, a--force is created by the. magnet which tends to move strips 25, 26 away from each other, this force being represented by vector F. Since the flexible strips 25, 26 are fixed at their otherends they cannot movein a direction'towardmagnet 27, and hence, the: only possible movement-which takes place is movement of the strips toward. oraway from each other due. to the flexibility of the strips. However, the only forces which act to move. thestripstowardv and. away from each" other are those represented" by vectors F'and A which act'to oppose each other. It has been discovered that one of these forces can be made predominant, to control the movement of the strips 25' and 26 toward each other or away from each other under the influence of the magnet. Thus, when the force repre sented'by vector P is the predominant force, the strips move away from each other, and when the predominant force'is the-force represented by vectors A the strips move toward each other.

Now consider the operation of reed switch .1. assh'cwn.

inFIG. 6, when influenced by a magnet-29. Magnet 29 is positioned'adjacent envelope 2 Withthe magnetic axis 3010f. themagnet midwaybetween andv parallel with reeds.

Inaddition to the forces 3 and 4. When so disposed it is apparent that the axis of the magnet is aligned with the axis of the switch, since the switch is symmetrical. The magnet attracts magnetic end members 12 and 13 and simultaneously induces poles of like polarity in each of the end members. Since the north pole of the magnet is closest to the end members, a south pole is induced in each end member. Hence, the influence of the magnet on magnetic end members 12 and 13 is to create forces which tend to move the end members apart by virtue of the repelling force of like poles, and also tend simultaneously to move the ends together to bring contacts and 11 into engagement by virtue of the attractive force of magnet 30. It is to be particularly noted that magnetic end members 12 and 13 are elongated in a transverse direction at right angles to axis 30 of magnet 29. With magnetic end members 12 and 13 so elongated, the attractive forces of magnet 30 become predominant and overcome the repelling forces due to the like polarity of end members 12 and 13. Since the reeds are resilient the attractive forces cause the ends to move toward each other so that contacts 10 and 11 engage under the influence of magnet 30 as shown in dotted lines in FIG. 6. As seen in FIG. 6 the Width of the pole of magnet 30, closest to switch 1, measured in a direction parallel with the aXes of end members 12 and 13 is slightly less than one half of the combined lengths, thus the areas, of the magnetic end members. By so proportioning the magnet, it is assured that the attractive forces of the magnet have an inwardly directed component such as that represented by vector A (FIG. 5). However, magnets of other dimension or configuration may be used with equal effectiveness so long as the attractive forces of the magnet have a component that moves the magnetic end members 12 and 13 toward each other. It is believed that elongating magnetic end mambers 12 and 13 in opposite directions and providing a magnet 30 having the described characteristics increases the angle of the inwardly acting attractive forces relative to axis 29 of the magnet. It therefore follows that the component of the attractive force tending to move ends 12 and 13 together is increased when the ends are elongated and a magnet of particular characteristics is used.

Turning to FIG. 7, the operation of switch 14 will now be described. A magnet 3-1 identical to magnet 30 is disposed so that its magnetic axis 32 is in aligned relation with and midway between the contact arms 19 and 20 of switch 14. Hence, it is apparent that center line 31 passes through the point of engagement of the normally closed contacts on end members 22 and 23 and is aligned with the axis of envelope 15. In this arrangement, the attractive forces have little, if any, effect on the switch, since each end member 22 and 23 is disposed closely adjacent the center line of the magnet. However, the magnet simultaneously induces like magnetic poles in each of the end members. These like poles tend to repel and it has been found that in this arrangement the forces due to magnetizing magnetic end members 22 and 23 to like polarity are predominant and are eifective to move the magnetic end members 22 and 23 away from each other to separate contacts 22' and 23 of switch 14 as shown in dotted lines in FIG. 7. It is believed that elongating magnetic end members 22 and 23 in the same transverse direction at right angles to the axis of envelope 15 so that the end members are narrow parallel members is effective to cause the repelling forces due to magnetizing end members 22 and 23 to like polarity to predomi nate. As shown in FIG. 7, the width of magnet 31 is greater than twice the diameter of each end member.

In the embodiments shown in FIGS. 1 and 3 the reeds are formed wholly of magnetic material. However, it is apparent that only those portions of the reeds that are influenced by the magnetic operator need be formed of magnetic material, since the magnetic operator affects only a short portion of each reed. Therefore, it is deemed within the scope of this invention to form the contact arm portions of the reeds of flexible nonmagnetic conductive 6 material, and to form the end members, and short portions of the reeds adjacent the end members of magnetic material.

The switches 1 and 14 are particularly adapted to be arranged in large numbers in side-by-side relation. When so arranged, the space requirements for a large number of these switches is substantially less than the space requirement for previously known switches. Also, since the terminals 6 and 18 project parallel to each other from the same end of the reed switch, they are well adapted to be inserted in suitable sockets, to both support the switches and to complete the electrical connections to the terminals.

FIG. 8 shows one particularly advantageous arrangement for the switches of this invention. As shown, switches 33-36 are grouped in rectangular array with the axes of the switches parallel. In this arrangement, the switches are fixedly mounted and are operated by electromagnetic actuators 42 arranged in a similar array. Each actuator includes a core 41 of magnetic material and a winding 42 on the core having leads 43 to connect the winding to a suitable electrical circuit (not shown). The electromagnets are so arranged that the axes of the cores of the electromagnets are aligned with the axes of reed switches 33 through 36. The cores of the electromagnets are disposed closely adjacent the dielectric envelopes of the switches so that energizing an electromagnet is effective to attract the magnetic end portions of the reeds of each switch while simultaneously magnetizing the ends to the same polarity to operate the switches selectively in the previously described manner.

Switches 33-36 may all be of the normally open type of FIG. 1, or of the normally closed type of FIG. 3, as several of each type may be used in the arrangement, since the same magnetic operator or actuator operates both types of switches. Although the switches are shown with the dielectric envelopes spaced slightly apart, the switches could be arranged with their envelopes in close contacting relation to further reduce the space required for a plurality of such switches when disposed in rectangular array.

FIG. 9 shows a ditference arrangement which further reduces the space required for a plurality of switches of this invention. As shown, switches 44-52 are arranged so that the envelope of any particular switch is closely adjawnt to or contacts the envelopes of at least two ther of the switches. When so arranged a portion of the space normally unused, when objects of circular configuration are arranged in side-by-side relation, is occupied by a portion of the cylindrical surface of the switches in adjacent rows. For example, the cylindrical surface of the envelope of switch 49 contacts the envelopes of switches 45 and 46 so that a portion of switch 49 is between switches 45 and 46. The lines connecting the axes of switches 45, 46 and 49 form an equilateral triangle since all the switches are of the same diameter. It is to be appreciated that the overall height of the switches of this arrangement is therefore less than the height of an arrangement in which the switches are in rectangular array and the switches in one row are aligned with those in the other rows. Magnetic operators for the switches of FIG. 9 are disposed in an array similar to that of the switches, with the axes of the magnetic operators aligned with the axes of the switches.

Now consider a particularly advantageous arrangement as shown in FIG. 10 for a plurality of reed switches which are required to be operated in sequence. As shown, switches 5360 are arranged in circular array in a cylindrical support 61 having a central bore 62. Mounted for rotation in cylindrical bore 62 is a shaft 63 having a driven end 64 which, when rotated, drives a magnet 65 in a circular path adjacent the ends of the reed switches. The magnet is mounted on an enlarged end 65 of shaft 63 so that an end 67 of the magnet is always slightly spaced a predetermined distance from the ends of the switches. Magnet 65 is so disposed that its magnetic ax-isisparallelwith the axes of eachof the reed switches and-is spaced the same distancefrom the axis of support 61 as the axes of the reed switches. Driven end 64 of the shaft isexternally'threaded so thata knurled member 68 can be threaded onto end '64, member 68 providing means for rotating the'ma-gnet via shaft 63. Rotating shaft 63 iseifective to move magnet 65 in a circular path so ,that'end .671passes in-close proximity to the ends of the reed switches. As'the magnet passes each switch, the switch is operated in the manner previously described. It istobe understood that the switches may be of either thenormally opentypeof-FIG. l or the normally closed type'of FIG. .3 ,,so that a circuitis either switched on'or oli by'the :action ofmagnet .65. For purposesof illustration :the magnet 67 :is shown :in the form of an =elongated :cy-linder. ,However, equally satisfying operation of the switches is =.realize.d by using an intensely :magnetized spot on thesurfaoe of a ferritic'disc, in lieu of magnet67 and-shaft en'd56. 'Of course, the magnetized spot is-properly located onthedisc and is so magnetized that .its magnetic axis is parallel with the axes of the switches.

,While only a preferred embodiment of the switches of this invention-have been described in detail, andonly several preferred arrangementsof the switch assemblies have been illustrated, it is to be understood that numerous changes canbe made in both the constructions of the switches as well as the arrangements of the switches withoutdepartingfrom the scope of this invention. Also it is to be understood that the switches will operate with their axes disposed in any. direction, for example, horizontal, vertical, or at anangle to-either of these directions. While only a preferred arrangement for sequential switching-hasbeenshown, it is also-to beunderstoo'd that the switches of this invention-can be used with equal advantage I in other known arrays for sequencingswitches.

What is 'claimed is: p

1. In a magnetically operated switch, the combination of:

an electrical switch assembly including a pair of opposed elongated members each with magnetic material at a common end of said pair of members to provide a pair of adjacent surfaces and a pair of transverse surfaces;

resilient means to provide relative-movement between said pair o'f'elongated members to open and close arr-associated set'ofelectrical contacts connected to said pair of members; and

selectively operable magnetic meansdisposed to create magnetic fields which indnce'like'magnetic poles in said pair of members at the common end thereof to create-a force-between said adjacent surfaces tendingto urge said pair ofmembers at the common end thereof each'away from the other, and which attracts the common end'of said pairof members along-said pair of transverse surfaces to create a force tending to urge said-pair of members-at the-common end thereof each toward-the other;

the areas ofthe pair of adjacent surfaces and thepair of transverse surfaces being arrangedrelative to one another in the magnetic fields so that one of .said forces'is predominant when said magnetic means is operated.

2. A-magnetically operated switch in accordance with claim 1, inwhich:

said set of contacts is normally closed, and

the predominant force is that force tending to urge the ends of said pair of members away from each other, to open said .contacts when said magnetic means is operated.

"magnet with means for energizing the electromagnet. 6. A magnetically operated switch in accordance with:

claim 11, in which:

said gswitch assembly includes an elongated non-- magnetic. envelope,

said pairs of members are portions of resilient reeds: disposed within said envelope Withihfi common end"v disposed adjacent one end of-said envelope,

said selectively operable magnetic means is disposed adjacent said one end of said envelope.

7. A magnetically operated switch in accordance with; I

claim '1, in which:

said switch assembly is sealedand further includes an:

elongated dielectric envelope, the pair of elongated members are of an electrically conductive material extending axially in the envelope each sealed to one end of said envelope in electrically insulated relationto the other, and terminating in transverse portion-s at said common end to provide the magnetic material at the other end of said envelope. 8. A magnetically operated switch in accordance with claim 1, inwhich:

at least one of the pair of members is flexible at least in part to provide said resilient means. 9. Amagnetically operated switch in accordance with claim 8 in which:

a plurality of said sealed switch assemblies are disposed in side=by-side axially aligned relation, and

each of .said' switch assemblies is provided with one of said magnetic operators adjacent an end thereof, and each of said magnetic operators is an electromagnet having a core, and a winding on said core. 10. ,A magnetically operated switch in accordance with claim 8 -in Which a plurality of said sealed switch assemblies are disposed in side-by side relation, and said magnetic operator is a magnet move-able along a path adjacentthe ends of said switch assemblies for operating said switches in sequence.

ReferencesCited by theExaminer UNITED STATES PATENTS 2,570,315 10/ 1951 Brewer 200-10 3 2,932,703 4/ 1960 Haberland 200-87 2,945,928 7/1960 Houser 200-87 3,061,696 10/1962 Peek 200-87 3,087,030 4/ 1963 Shebanow 200-87 FOREIGN PATENTS 536,695 5/1951 Great Britain.

BERNARD A. GILHEANY, Primary Examiner.

7 0 I. J. BAKER, Assistant Examiner. 

1. IN A MAGNETICALLY OPERATED SWITCH, THE COMBINATION OF: AN ELECTRICAL SWITCH ASSEMBLY INCLUDING A PAIR OF OPPOSED ELONGATED MEMBERS EACH WITH MAGNETIC MATERIAL AT A COMMON END OF SAID PAIR OF MEMBERS TO PROVIDE A PAIR OF ADJACENT SURFACES AND A PAIR OF TRANSVERSE SURFACES; RESILIENT MEANS TO PROVIDE RELATIVE MOVEMENT BETWEEN SAID PAIR OF ELONGATED MEMBERS TO OPEN AND CLOSE AN ASSOCIATED SET OF ELECTRICAL CONTACTS CONNECTED TO SAID PAIR OF MEMBERS; AND SELECTIVELY OPERABLE MAGNETIC MEANS DISPOSED TO CREATE MAGNETIC FIELDS WHICH INDUCE LIKE MAGNETIC POLES IN SAID PAIR OF MEMBERS AT THE COMMON END THEREOF TO CREATE A FORCE BETWEEN SAID ADJACENT SURFACES TENDING TO URGE SAID PAIR OF MEMBERS AT THE COMMON END THEREOF EACH AWAY FROM THE OTHER, AND WHICH ATTRACTS THE COMMON END OF SAID PAIR OF MEMBERS ALONG SAID PAIR OF TRANSVERSE SURFACES TO CREATE A FORCE TENDING TO URGE SAID PAIR OF MEMBERS AT THE COMMON END THEREOF EACH TOWARD THE OTHER; THE AREAS OF THE PAIR OF ADJACENT SURFACES AND THE PAIR OF TRANSVERSE SURFACES BEING ARRANGED RELATIVE TO ONE ANOTHER IN THE MAGNETIC FIELDS SO THAT ONE OF SAID FORCES IS PREDOMINANT WHEN SAID MAGNETIC MEANS IS OPERATED. 